1/ It is not possible to create objects dynamically, you have to define them in the test explicitly - when your data file contains 3 object, you have to do following:
TestObject to1 = new TestObject()
TestObject to2 = new TestObject()
TestObject to3 = new TestObject()
... and then it is possible to assign properties using parser script using to1.addProperty() method.

I'd recommend you to rewrite your Excel file into a single custom keyword, where you create all your TestObjects and then initialize it in a test. It may look like this:

And then it is very simple to use them wherever you want:
(you don't have to create an instance of MyTestObjects as all objects are static).

Please visit this page to get more info about creating TestObjects and manipulating with its properties.